Square Releases Open Source WebSocket Client for Objective-C | Hacker News Reader

Square Releases Open Source WebSocket Client for Objective-C

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175 pointsmikelikespie19 comments

Is there any reason to use WebSockets on native apps other than if you want to share one server between native and web?

Only reason I can think of is to traverse firewalls that block outbound sockets but don't block HTTP+WebSocket.

That aside, it seems a bit ridiculous, given that we already have sockets, to bolt on a protocol that exists almost solely to work around security issues involved in a browser opening a socket.

I think it's the same reason you would want to use good old HTTP over raw sockets for a request/response API, even though with a native client you could just invent your own protocol.

If you want bidirectional communication to your app, it's much easier to make a server that uses the WebSocket Protocol (tornado, etc.) instead of rolling your own server and protocol.

Thank god. I have worked extensively with cocoa-websocket and socketio-cocoa and they are a complete mess.

Square has done a lot for iOS open source, with their unit test framework and other libraries and now this.

So, following up on the link in another comment on this article [1] to socket.IO-objc [2], one goes through a few forks of cocoa-websocket [3,4,5] to arrive at zimt [6].

Are there reasons to use SocketRocket over these other libraries (either socket.IO-objc, or the various forked lineage of cocoa-websocket/zimt)?

(Also, to ask the question I always have to ask: is there a reason for a new library rather than contributing to one of the existing ones, possibly even helping Unitt support RFC6455?)

[1] http://news.ycombinator.com/item?id=3563527 [2] https://github.com/pkyeck/socket.IO-objc [3] https://github.com/samlown/cocoa-websocket [4] https://github.com/adamjernst/cocoa-websocket [5] https://github.com/erichocean/cocoa-websocket [6] https://github.com/esad/zimt

Cocoa-websocket doesn't seem to support the latest standard[1]. You can tell because the handshake has key1 and key2 which is protocol 00[2]

Re: socket.IO, I haven't actually used it, so correct me if my assumptions are wrong, but the objc client doesn't seem to use WebSockets as a transport. So I imagine you can get the same bidirectional semantics if by using socket.IO-objc if you want to limit yourself to servers written in node (or have a socket.IO bridge).

However, why not go with standards? Since socket.IO supports websockets, the objc implementation could be backed by SocketRocket easily.

My two biggest complaints against Unitt & cocoa-websocket aside from them not supporting RFC6455 is having CocoaAsyncSocket as a dependency.

I've dug deep into it's implementation, and even had a prototype of SocketRocket that used it (basically went from CocoaAsync to dispatch_io to CFStream), and I'm not too impressed. Also, CocoAsync 2x or 3x more code than the entire WebSocket implementation without it. It also has drastically different codepaths for iOS and Cocoa and it's very difficult to see what's going on. Makes testing more difficult.

The other reason I decided to roll my own is just a learning experience. At first I wanted an excuse to play with new libdispatch io stuff[3].

[1] https://github.com/samlown/cocoa-websocket/blob/master/WebSo...

[2] http://en.wikipedia.org/wiki/WebSocket#draft-ietf-hybi-thewe...

[3] http://www.opensource.apple.com/source/libdispatch/libdispat...

We are currently using UnittWebSocketClient in our iOS app to communicate with a Tornado server:

http://code.google.com/p/unitt/wiki/UnittWebSocketClient

It has worked well so far, but I'm glad to see more activity in this area.

The reason Unitt didn't work for us is that it isn't updated to work with the latest WebSocket protocol. This is an issue, especially since there's finally a standard (RFC 6455)

tools.ietf.org/html/rfc6455

Tornado is nice since it implements some of the legacy versions of WebSockets, but there are many servers that will probably deprecate them sooner rather than later.

You guys are constantly pushing out cool stuff, just started using KIF and I really like it. Thanks for open sourcing guys!

Great to see this... I've been using libPusher, but it's specific to the Pusher service (which is actually pretty great).

Perhaps libPusher can just start using SocketRocket as a dependency and wrap it in Pusher-specific goodness...

This would be cool. We've been experimenting with uses for WebSockets. One of them is mocking push notifications in the simulator. The other is basically implementing a pusher-like service with a pub-sub model.

Pusher-like service implementations are very easy, I know, I've built one[1] and there are others[2]!

If you have any questions, feel free to email me.

[1] https://github.com/danbeaulieu/PushPlay

[2] https://github.com/stevegraham/slanger

Rad! Somebody pointed out slanger to me previously, but I was unaware of PushPlay. Thanks!

If I'm using Socket.IO via an Obj-C lib, is there a point to taking a look at this? Should the Socket.IO community look at integrating this as the engine behind the client on Obj-C, or is there little/no benefit?

I'm unsure what you mean by "Socket.IO via an Obj-C lib". Could you send a link? It looks like Socket.IO is node (which I don't believe you can use in iOS).

He means communicating with a Socket.IO server from Obj-C (most probably also using web sockets but speaking the Socket.IO protocol).

Here's a link to a socket.io client library in Obj-C:

https://github.com/pkyeck/socket.IO-objc

Does this get around the shitty reverse-proxies mobile providers set up that kill websocket connections?

I can't answer this yet. I'd be curious to hear

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